Step 2 UWorld Self-Assessment (UWSA) 2 Practice Exam

This scenario points to a gestational trophoblastic neoplasm, specifically choriocarcinoma, arising after a pregnancy event. Choriocarcinoma is highly vascular and secretes large amounts of hCG, so the uterus becomes symmetrically enlarged and vaginal or cervical metastases are common. A red, friable vascular nodule in the posterior fornix that bleeds easily is a classic appearance of a vaginal metastasis from this tumor. Endometrial carcinoma would more typically present with abnormal uterine bleeding in an older patient and not with a friable vaginal vascular lesion. Ovarian cystadenocarcinoma would usually present with an adnexal mass and ascites rather than a vascular vaginal nodule. Leiomyosarcoma causes rapid uterine enlargement and uterine symptoms but lacks the characteristic hemorrhagic vaginal metastasis. So, the presentation aligns best with choriocarcinoma.